From: Joe Jin <joe.jin@oracle.com>
Date: Mon, 27 Aug 2012 05:26:13 +0000 (+0800)
Subject: tg3: Add memory barriers to sync BD data
X-Git-Tag: v2.6.39-400.9.0~338^2~156
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e4fd485f6b9da3a094413e525c563c61b3988b08;p=users%2Fjedix%2Flinux-maple.git

tg3: Add memory barriers to sync BD data

for weak memory model architectures to ensure that the chip will DMA
valid BD data.

(cherry picked from commit 6541b806b5f267eda8f127bb7f5fec4e7e4db995)
Signed-off-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Reviewed-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Joe Jin <joe.jin@oracle.com>
---

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 683198897476..65ad7fd66194 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -5921,6 +5921,9 @@ next_pkt_nopost:
 
 	/* Refill RX ring(s). */
 	if (!tg3_flag(tp, ENABLE_RSS)) {
+		/* Sync BD data before updating mailbox */
+		wmb();
+
 		if (work_mask & RXD_OPAQUE_RING_STD) {
 			tpr->rx_std_prod_idx = std_prod_idx &
 					       tp->rx_std_ring_mask;
@@ -6972,6 +6975,9 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			goto drop_nofree;
 	}
 
+	/* Sync BD data before updating mailbox */
+	wmb();
+
 	/* Packets are ready, update Tx producer idx local and on card. */
 	tw32_tx_mbox(tnapi->prodmbox, entry);
 
@@ -11772,6 +11778,9 @@ static int tg3_run_loopback(struct tg3 *tp, u32 pktsz, bool tso_loopback)
 
 	tnapi->tx_prod++;
 
+	/* Sync BD data before updating mailbox */
+	wmb();
+
 	tw32_tx_mbox(tnapi->prodmbox, tnapi->tx_prod);
 	tr32_mailbox(tnapi->prodmbox);